Myoglobin is a protein used in animal muscle to store oxygen. (It is a close relative of hemoglobin, which carries oxygen in the blood.) The oxygen in both hemoglobin and myoglobin is bound to a large nonprotein molecule called a heme, which is tightly bound to the protein itself.

The heme binding site consists of a [...]

Certain neutron-poor isotopes, for example, 11C and 18F, are very short-lived (about 20 and 103 min, respectively) and decay by converting protons into neutrons. In the process, positrons (positively-charged electrons) are produced. [...]

Analytical chemistry is important in many disciplines and may provide crucial information to a geologist, an atmospheric physicist, or [...]